Recovering non-conventional water sources to combat water scarcity

Focusing on water scarce decentralised areas, the case of the EU funded project HYDROUSA

The European Commission’s Circular Economy Action plan targets on “closing the loop” of valuable recourses and products. Implementing innovative solutions, the goal is to abandon the ‘take-make-dispose’ culture, by recovering and reusing resources and products. Within Horizon2020, the EU is investing approximately € 1 billion on circular economy projects within the period 2018-2020, including water related projects. On the water sector in particular, the development of water services, which ‘go beyond water supply sustainability addressing the different water value chains’ is promoted. Reclaimed water reuse is at the top of these priorities.

HYDROUSA, a Horizon 2020 Research & Innovation project funded by the EU, inspired by this ‘philosophy’,  aims to recover water from non-conventional water sources by capitalising on the rational management of water resources. It supports the new EU Regulation on minimum requirements for water reuse for agricultural irrigation. Our goal is to close the water loops and boost the agricultural and the energy profile in the Mediterranean region using nature-based and nature-inspired innovative systems at local level. 28 partners from 10 countries are involved in the project which is coordinated by the Sanitary Engineering Laboratory of the National Technical University of Athens.

The Islands of Lesbos, Tinos and Mykonos are hosting six full scale demonstration sites (HYDRO1-6), where sustainable innovative and nature-based solutions for water/wastewater treatment and management are developed within the framework of HYDROUSA.

In Lesbos Island, low-cost reclaimed water is produced combining anaerobic processes (Upflow Anaerobic Sludge Blanket – UASB) and constructed wetlands (two-stage subsurface vertical flow) for the treatment of the domestic wastewater of Antissa village (HYDRO1). After disinfection, the nutrient rich water is used for fertigation of 1 ha agroforestry system (HYDRO2). The biogas produced is upgraded to methane and used as fuel for local vehicles. This solution is a self-sustaining wastewater management system where water, nutrients and the produced sludge are reused with significant economic benefits from the agroforestry system.

In Mykonos Island, where the cost of water or even the non-availability of water are putting severe pressure on the agricultural growth, rainwater harvesting systems are developed.  HYDRO3 in Ano-Mera village consists of a novel, subsurface rainwater harvesting system developed in a remote agricultural area. The collected rainwater is used to irrigate an oregano field which is then valorised to produce essential oils. In HYDRO4, rainwater and surface runoff are collected and stored into the aquifer during the wet season and are used domestically and for agricultural production (lavender cultivation) during the dry season.

In Tinos Island, the demos implemented seek alternative, sustainable solutions to treat and recover water and valuable products. HYDRO5, is a nature-inspired, low-cost desalination system based on the principles of evaporation and condensation, located in Tinos. The Mangrove still system (inspired by the Mangrove plant) produces irrigation water and edible salt combined with a greenhouse to produce tropical fruits that will be consumed locally. Tinos Ecolodge (HYDRO 6) is an eco-tourist facility exhibiting a self-sufficient management cycle of water, energy, and food. Rainwater and vapour water recovery systems are demonstrated within the facilities. Furthermore, wastewater is treated by reedbeds and is recycled locally in agriculture.

We are thrilled to step into HYDROUSA’s most important phase, as almost all the project’s solutions are already developed and operational. We have two upcoming years for demonstration, to show how circularity can be the solution to water scarcity supporting at the same time sustainable agricultural development and biodiversity.

HYDROUSA’s solutions have been co-developed by the relevant stakeholders (farmers, water-utilities, tourist businesses) within co-creation workshops, so their needs and views are included. The HYDROUSA consortium has developed policy briefs on how the project supports the European Green Deal and on the revisions within the UWWTD. HYDROUSA has also attracted the attention of the scientific community and investors. Within the achievements of the first two years of the project are the development of a methodology on circularity assessment, which is already applied by large companies, several publications in prestigious peer reviewed journals, and the development of an innovative monitoring tool for precision irrigation, which is already on the market.

Simos Malamis, Eleni Nyktari, Stavroula Kappa, Daniel Mamais, Constantinos Noutsopoulos
National Technical University of Athens 

HYDROUSA has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No. 776643